Check valve

ABSTRACT

A top entry check valve including a valve body with an access port. A compressible hanger body engages a portion of the valve body and is positioned in alignment with the access port of the valve body. A clapper is connected to the hanger body so that the clapper is movable between a closed position wherein the clapper engages a valve seat to occlude the passage of fluid through the fluid flow passage and an open position wherein the clapper is moved away from the valve seat to permit passage of fluid through the fluid flow passage. A closure member is connected to the valve body to close the access port of the valve body. The closure member has an abutment surface engaging the hanger body so that the hanger body is compressed between the closure member and the valve body.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/990,071, filed Nov. 16, 2004, which is incorporated herein byreference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to valves and more particularly, butnot by way of limitation, to a check valve particularly designed andconstructed for facilitating repair and maintenance of the valve whenworn or otherwise damaged.

2. Brief Description of Related Art

Check valves are old and well known for use in flow lines where it isdesirable to permit fluid flow in one direction and preclude fluid flowin the opposite direction. A common structure for achieving one-way flowis by the use of a disk or clapper that is positioned so that it canpivot about an axis of a pivot shaft. The disk is loosely retained inposition between a recess formed in the valve body and the lower edge ofa bonnet used to close an access port.

In non-corrosive applications, such a structure generally allows for areasonable service life. In most applications, however, in particularpetroleum production, corrosive constituents generally exist within theflow media. Even when the flow media is only mildly corrosive, thecombined action of the corrosion and the erosion created by vibrationand the rubbing movement of the pivot shaft against the valve body andthe bonnet often causes a loss of surrounding metal which may result infailure of the valve due to misalignment of the disk. One solution tothis problem would be to make the entire valve from stainless steel orsome other corrosion resistant material. While this would solve thecorrosion problem, the cost of the valve would greatly increase andwould not be economically viable.

To this end, a need exists for an improved check valve that is capableof being used in a corrosive environment yet is cost effective tomanufacture and repair. It is to such an improved check valve that thepresent invention is directed.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a sectional view of a check valve constructed in accordancewith the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1.

FIG. 3 is a side elevational view of a clapper assembly.

FIG. 4 is a rear elevational view of the clapper assembly of FIG. 3.

FIG. 5 is a side elevational view of a portion of the clapper assemblyshown mounted to a valve body and in a low pressure condition.

FIG. 6 is a side elevational view of a portion of the clapper assemblyshown mounted to the valve body and in a high pressure condition.

FIG. 7 is a side elevational view of a portion of another embodiment ofa clapper assembly shown mounted to a body.

FIG. 8 is a sectional view of another embodiment of a check valveconstructed in accordance with the present invention.

FIG. 9 is a rear elevational view of a portion of the clapper assemblyof FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly to FIGS. 1 and 2, avalve 10 constructed in accordance with the present invention is shown.The valve 10 includes a valve body 12, a clapper assembly 14, and aclosure member 16. The clapper assembly 14 cooperates with the valvebody 12 to permit fluid flow in one direction while preventing fluidflow in the opposite direction. As such, the valve 10 is of the typecommonly known as a “swinging check valve.”

The valve body 12 has a first end 17 with an inlet port 18 and a secondend 19 with an outlet port 20 which is generally opposing the inlet port18. The inlet port 18 extends into the valve body 12 and opens into avalve chamber 22 formed in a medial portion of the valve body 12. Anannular valve seat 24 is defined about the inlet port 18. The valve seat24 is shown to be formed as an integral part of the valve body 12.However, it will be appreciated that the valve seat 24 may be formed ona module that is inserted into the valve body 12. The outlet port 20extends into the valve body 12 and opens into the valve chamber 22generally opposite the inlet port 18. The inlet port 18 and outlet port20 are shown to be internally threaded to provide a means for connectingthe valve 10 into a conduit utilized for transporting a fluid. However,it will be appreciated that the inlet port 18 and the outlet port 20 maybe adapted to be interposed in a flow line in other ways, such as beformed with flanges.

The first end 17 of the valve body 12 includes a shelf portion 26 whichextends into the valve chamber 22 and defines a portion of the inletport 18. The shelf portion 26 includes a generally flat bearing surface28 for supporting the clapper assembly 14 in a manner to be discussedbelow. A pin receiving hole 30 is formed through the bearing surface 28and into the shelf portion 26 along a center line of the valve body 12.

The upper portion of the valve body 12 is provided with an access port32 which is in communication with the valve chamber 22. The access port32 is threaded and sized to allow passage of the clapper assembly 14 toand from the valve chamber 22 via the access port 32. The shelf portion26 of the valve body 12 projects into alignment with the access port 32such that the bearing surface 28 faces the access port 32 and thus isaccessible via the access port 32.

The closure member 16 functions to seal the access port 32 and thus hasexternal threads to mate with threads or the access port 32. The closuremember 16 further has a flange 34 for compressing a seal member 36, suchas an elastomeric O-ring, disposed in a groove 38 of the valve body 12.The seal member 36 is compressed to effect a fluid tight seal betweenthe closure member 16 and the valve body 12 when the closure member 16is threaded onto the valve body 12 with the flange 34 engaging the valvebody 12.

The closure member 16 further includes an abutment surface 40 defined bya lower end of the closure member 16. The abutment surface 40 serves toengage a portion of the clapper assembly 14 and thus cooperate with thevalve body 12 to fix the clapper assembly 14 within the valve chamber22. The size and position of the abutment surface 40 may varied so longas the abutment surface 40 engages the clapper assembly 14 when theclosure member 16 is operably secured to the valve body 12 to effect afluid tight seal. However, the abutment surface 40 is preferably annularin so far as the abutment surface 40 may slidingly engage the clapperassembly 14 as the closure member 16 is being secured to the valve body12.

Referring now to FIGS. 1-4, the clapper assembly 14 includes a hanger 42and a clapper 44 pivotally mounted to the hanger 42 with a pivot shaft46. The hanger 42 is adapted to be firmly held between the bearingsurface 28 of the valve body 12 and the abutment surface 40 of theclosure member 16 and thereby support the clapper 44 in alignment withthe inlet port 18. With reference to FIGS. 3-4, the hanger 42 includes abody member 48, an alignment pin 50 extending from one side of the bodymember 48, and a compressible member 52 connected to an opposing side ofthe body member 48.

The body member 48 is shown to be a generally cubicle member with a bore54 extending therethrough from one side to an opposing side. However, itwill be appreciated that the body member 48 may be formed of a varietyof shapes so long as the body member 48 functions to pivotally supportthe clapper 44 and is securable between the bearing surface 28 of thevalve body 12 and the abutment surface 40 of the closure member 16 inthe manner to be described below. The alignment pin 50 extends from thebody member 48 and is adapted to be matingly received in the pinreceiving hole 30 of the valve body 12. The alignment pin 50 ispositioned so that the clapper assembly 14 may be supported within thevalve chamber 22 with the clapper 44 aligned with the inlet port 18prior to the closure member 16 being secured to the valve body 12.

The compressible member 52 is connected to a side of the body member 48opposite the alignment pin 50 such that the combination of thecompressible member 52 and the body member 48 are capable of being heldfirmly between the bearing surface 28 of the valve body 12 and theabutment surface 40 of the closure member 16 when the closure member 16is operably secured to the valve body 12. The function of thecompressible member 52 is to cause the clapper assembly 14 to be heldfirmly in position between the valve chamber 22 and the closure member16 while compensating for differences in dimension to the variouscomponents of the valve 10 due to normal manufacturing tolerances. Forexample, if a non-compressible body member were sized to be positionedalone between the closure member 16 and the valve body 12, in someinstances the dimensions of the components of the valve 10 would resultin the closure member 16 being properly sealed with the valve body 12and the clapper assembly 14 being held in position without vibration orrubbing occurring between the clapper assembly 14 and the closure member16 and/or the valve body 12.

However, in other instances when the dimensions of the components of thevalve cause the distance between the bearing surface 28 of the valvebody 12 and the abutment surface 40 of the closure member 16 to bedecreased, the body member 48 would interfere with the closure member 16being properly sealed to the valve body 12, thereby increasing the riskthat the valve 10 would leak. On the other hand, if the dimensions ofthe components of the valve are such that the distance between thebearing surface 28 of the valve body 12 and the abutment surface 40 ofthe closure member 16 are increased, the height of the body member wouldbe less than the distance from the bearing surface 28 to the abutmentsurface 40. As such, the closure member 16 would not engage the bodymember 48 before the closure member 16 is secured to the valve body 12.Consequently, the combined action of corrosion and the erosion createdby vibration and the rubbing movement of the body member against thevalve body 12 and the closure member 32 would rapidly cause a loss ofsurrounding metal which may result in failure of the valve 10 due tomisalignment of the clapper 44.

The compressible member 52 is preferably some type of compressionspring. The compressible member 52 is illustrated herein as being a“flat” spring formed from a strip material 56 to have a general U-shapewith an intermediate portion 58 and two opposing end portions 60. Thecompressible member 52 is oriented in a substantially parallelrelationship to the bore 54 of the body member 48 whereby the stripmaterial 56 is tangentially positioned relative to the abutment surface40 of the closure member 16. The end portions 60 of the strip material56 are curved so that the end portions 60 of the strip material 58 curveaway from the access port 32 to facilitate sliding engagement with theabutment surface 40 of the closure member 16. The compressible member 52is connected to the body member 48 in a suitable fashion, such as with apin, rivet or weld, or alternatively, the body member 48 and thecompressible member 52 may be formed as a single piece.

The hanger 42, including the body member 48, the alignment pin 50, andthe compressible member 52 are fabricated of a corrosion resistantmaterial, such as stainless steel. The compressible member 52 ispreferably resilient whereby the compressible member 52 is capable ofrecovering its shape after being deformed by the application of forcecaused by securing the closure member 16 to the valve body 12. However,it should be appreciated that the compressible member 52 may be formedof a material that becomes permanently deformed upon being compressed bythe application of force so long as the compressible member 52 maintainssufficient tension against the abutment surface 40 so that the hanger 42is held firmly between the closure member 16 and the valve body 12. Itwill also be appreciated that while the compressible member 52 has beendescribed and illustrated as being engaged with the closure member 16,the compressible member 52 may alternatively be positioned on the bodymember 48 so that the compressible member 52 engages the valve body 12.

The clapper 44 is pivotally secured to the body member 48 with the pivotshaft 46 and cooperates with the valve seat 24 to provide alternate openand closed positions for the valve 10. The clapper 44 includes asubstantially circular disc member 62 adapted to engage the valve seat24 in the closed position of the valve 10. A suitable sealing member,such as an O-ring 64, is disposed in an annular groove 66 for engagingthe valve seat 24 to preclude leakage of fluid in the closed position ofthe valve 10. Alternatively, the sealing member may be disposed in thevalve seat 24 instead of on the disc member 62.

A pair of arms 68 extend from the disc member 62 in a spaced apart,parallel relationship. The arms 68 are spaced a sufficient distance toreceive the body member 48 therebetween. The distal end of the arms 68is provided with a bore 70 (FIG. 4) extending transversely therethroughfor receiving the pivot shaft 46 therein. The pivot shaft 46 may besecured within the bores 70 of the arms 68 and the bore 54 of the bodymember 48 in any suitable manner, such as securing a fastener on theends, forming a head on the ends of the pivot shaft 46 by enlarging orflattening the ends of the pivot shaft 46, or providing the pivot shaft46 with a length where the ends of the pivot shaft 46 are positionednear the interior surface of the valve body 12. The distal end of thearms 68 are offset relative to the center of gravity of the disc member62. As such, the pivot axis of the clapper assembly 14 is offset fromthe center of gravity of the disc member 62, thus causing the discmember 62 to be constantly urged in a direction toward the valve seat 24in a normally closed position.

FIGS. 3 and 4 illustrate the bore 54 of the body member 48 beingoversized relative to the pivot shaft 46 whereby the pivot shaft 46 isable to move laterally within the bore 54 to permit an amount of freeplay between the pivot shaft 46 and the body member 48. Such free playallows the clapper 44 to properly align with the valve seat 24 upon theclapper 44 moving to the closed position, thereby compensating for anypotential misalignment of the clapper 44 with the valve seat 24 due towear or manufacturing tolerances.

As illustrated in FIGS. 5 and 6, the free play between the pivot shaft46 and the body member 48 further permits the clapper 44 to movelinearly along an axis 72 of the inlet port 18 in response to variancesin line pressure. More specifically, the free play between the pivotshaft 46 and the body member 48 permits the clapper 44 to move along theaxis 72 of the inlet port 18 whereby a uniform pressure is maintained onthe seal member 64 in a low pressure condition (FIG. 5) and a highpressure condition (FIG. 6).

FIG. 7 illustrates another embodiment of a clapper 44 a having arms 68a. Each arm 68 a is provided with a bore 70 a that is elongated whereinthe elongated bores 70 a allow axial movement of the clapper 44 a in amanner similar to that described above to effect a uniform compressionseal.

The above described construction of the valve 10 permits rapid repair ofthe valve 10 without requiring the valve body 12 being removed from theflow line. In particular, access to the clapper assembly 14 is obtainedby unscrewing the closure member 16 from the valve body 12. With theclosure member 16 removed from the valve body 12, the clapper assembly14 can be grasped and withdrawn from the valve body 12 via the accessport 32. A new clapper assembly 14 may then be inserted into the valvebody 12 by inserting the alignment pin 50 in the pin receiving hole 30.The closure member 16 is then threaded onto the valve body 12 so thatthe abutment surface 40 of the closure member 16 engages and compressesthe compressible member 52 of the hanger 42 and forces the body member48 firmly against bearing surface 28 of the valve body 12.

Where fluid pressure is applied at the inlet port 18, such pressurebears against the disc member 62 of the clapper 44 to force the clapper44 out of engagement with the valve seat 24 to provide a flow passagethrough the valve chamber 22 from the inlet port 18 to the outlet port20 so that fluid will flow through the valve 10. When fluid pressure isapplied at the outlet port 20, the weight of the clapper 44 cause theclapper 44 to pivot to the closed position wherein the disc member 62engages the valve seat 24 to occlude the passage of fluid through thevalve 10.

Referring now to FIG. 8 and 9, a valve 10 a constructed in accordancewith the present invention is illustrated. The valve 10 a is similar inconstruction to the valve 10 described above, with the exception thevalve 10 a is provided with a modified clapper assembly 14 a. Theclapper assembly 14 a is similar to the clapper assembly 14 describedabove, but the clapper assembly 14 a is provided with features that mayenhance the performance of the clapper assembly 14 a over that of theclapper assembly 14. First, the clapper assembly 14 a is provided with acounterweight 80 on a clapper 44 b to facilitate movement to the closedposition in both horizontal and vertical service. The clapper 44 b isfurther shown to have a pair of return springs 82 and 84 (FIGS. 8 and 9)to further facilitate rapid closure of the clapper 44 b by biasing theclapper 44 b in the closed position. The return springs 82 and 84 alsoreduce slamming of the clapper 44 b caused by pressure reversal.Finally, the valve 10 a is shown to be provided with a cushion spring 86positioned to receive the clapper 44 b and thus absorb the impact of theclapper 44 b upon rapid opening of the clapper 44 b.

From the above description, it is clear that the present invention iswell adapted to carry out the objects and to attain the advantagesmentioned herein as well as those inherent in the invention. Whilepresently preferred embodiments of the invention have been described forpurposes of this disclosure, it will be understood that numerous changesmay be made which will readily suggest themselves to those skilled inthe art and which are accomplished within the spirit of the inventiondisclosed and as defined in the appended claims.

1. A valve, comprising: a valve body having an inlet port, an outletport, a flow passage extending between the inlet port and the outletport, and an access port; a valve seat defined about the inlet port ofthe valve body; a compressible hanger in contact with the valve body andpositioned in alignment with the access port of the valve body; aclapper supported by the hanger so that the clapper is movable between aclosed position wherein the clapper engages the valve seat to occludethe passage of fluid through the fluid flow passage and an open positionwherein the clapper is moved away from the valve seat to permit passageof fluid through the fluid flow passage; and a closure member connectedto the valve body to close the access port of the valve body, theclosure member having an abutment surface in contact with the hanger sothat the hanger is compressed between the closure member and the valvebody.
 2. The valve of claim 1 wherein the hanger comprises a body memberand a compressible member extending from one side of the body member,the compressible member being compressed upon the closure member beingoperably connected to the valve member.
 3. The valve of claim 2 whereinthe compressible member is resilient.
 4. The valve of claim 2 whereinthe compressible member is positioned between the body member and theclosure member.
 5. The valve of claim 2 wherein the compressible memberis a substantially U-shaped strip material having opposing ends and amedial portion, the medial portion being connected to the body member.6. The valve of claim 5 wherein the closure member is threadinglyconnected to the valve member, and wherein the opposing ends of thestrip material curve away from the abutment surface of the closuremember to facilitate sliding engagement between the abutment surface ofthe closure member and the ends of the strip material as the closuremember is being threadingly connected to the valve body.
 7. The valve ofclaim 5 wherein the closure member is threadingly connected to the valvemember, wherein the strip material is oriented on the body member suchthat a longitudinal axis of the strip material is tangentiallypositioned relative to the abutment surface of the closure member, andwherein the opposing ends of the strip material curve away from theabutment surface of the closure member to facilitate sliding engagementbetween the abutment surface of the closure member and the ends of thestrip material as the closure member is being threadingly connected tothe valve body.
 8. The valve of claim 1 wherein the hanger has analignment pin extending from one side thereof and wherein the valve bodyis provided with a pin receiving hole for receiving the alignment pin ofthe hanger to support the hanger on the valve body prior to the closuremember being connected to the valve body.
 9. The valve of claim 1wherein the clapper is movable along a longitudinal axis of the inletport.
 10. The valve of claim 9 wherein the hanger has a bore extendingtherethrough and wherein clapper is connected to the hanger with a pivotshaft extending through the bore, the bore being sized to permit lateralmovement of the pivot shaft in the bore.
 11. The valve of claim 9wherein the hanger has a bore extending therethrough and wherein clapperis connected to the hanger with a pivot shaft extending through thebore, the clapper having a pair of arms provided with bores forreceiving the pivot shaft, the bores of the arms being elongated topermit lateral movement of the clapper relative to the pivot shaft. 12.The valve of claim 1 wherein the clapper is provided with acounterweight.
 13. The valve of claim 1 wherein the valve body isprovided with a cushion spring positioned to engage the clapper when theclapper is in a full open position.
 14. The valve of claim 1 wherein theclapper further comprises means for biasing the clapper in the closedposition.
 15. A valve, comprising: a valve body having an inlet port, anoutlet port, a flow passage extending between the inlet port and theoutlet port, and an access port; a valve seat defined about the inletport of the valve body; a spring positioned between the valve body andthe access port of the valve body; a clapper connected to the spring sothat the clapper is movable between a closed position wherein theclapper engages the valve seat to occlude the passage of fluid throughthe fluid flow passage and an open position wherein the clapper is movedaway from the valve seat to permit passage of fluid through the fluidflow passage; and a closure member removably connected to the valve bodyto selectively close and open the access port of the valve body, theclosure member having an abutment surface in contact with the spring soas to compress the spring between the closure member and the valve body.16. The valve of claim 15 wherein the spring is resilient.
 17. The valveof claim 15 wherein the clapper is movable along a longitudinal axis ofthe inlet port.
 18. The valve of claim 15 wherein the clapper isprovided with a counterweight.
 19. The valve of claim 15 wherein thevalve body is provided with a cushion spring positioned to engage theclapper when the clapper is in a full open position.
 20. The valve ofclaim 15 wherein the clapper further comprises means for biasing theclapper in the closed position.